Although undertreatment of pain for hospitalized children has been well documented, few studies have examined ways to alleviate the problem., Physicians' failure to prescribe adequate analgesics and nurses' failure to effectively administer them may be related to a myriad of factors related to the child, health care professional, and hospital setting. Despite the complexity of pain assessment and management, decisions affecting pain relief are rarely guided by formal policies. The purpose of this study is to examine the effects of implementing a pain management policy. The specific aims are to: (1) refine the policy; (2) evaluate the effectiveness of policy implementation on four outcome variables: provider attitudes about pain, provider behaviors related to pain, pain-related patient-centered outcomes, and cost factors related to recovery; (3) describe relevant contextual factors; and (4) evaluate the feasibility and cost-benefits of policy implementation. A quasi-experimental design guides the study in eight pediatric units selected from regional hospitals. Two units at a time, paired for type, location, and size, are randomly assigned to experimental and control status. Experimental units (n=4) will receive training and materials to implement a pain management policy that includes pain histories on admission, pain assessment every four hours using a behavioral observation tool and a pain rating scale, intervention for pain using standardized guidelines, reassessment in one hour to determine effectiveness, and documentation on pain flow sheets. Pain assessment and management practices will be closely monitored in both experimental and control units during a four-month Baseline Phase, five-month Implementation Phase, and six-month Maintenance Phase. Data are collected from nurses, physicians, children, parents, patient records, and other documents. Outcome variables will be documented throughout the study to determine changes over time. Qualitative and quantitative analyses including multivariate analysis of variance using a factorial design address the aims with findings integrated through triangulation. Results from contextual, feasibility, and cost-benefit analyses enhance the interpretability of the quasi-experimental design findings. The proposed research would be the first study to examine the effects of an intervention for undertreatment of children's pain. The comprehensive, comparative data generated by this research have landmark potential for guiding research and practice toward effective solutions for unresolved pain in hospitalized children.